“It’s far from easy, Jimmy. As the ‘rope’ rises above the ground, the magnetic force diminishes very rapidly. To raise a ‘rope’ twenty feet takes something like a baby cyclotron. Making one would take years of work and cost a small fortune.”
“Three years and fifty thousand dollars,” Mustapha broke in. “At least so Dr Marlin told me. But the reward was enormous.”
“But what happened to Ali; how did he vanish from the top of the rope?” I asked.
“Let’s take things in order,” my uncle said. “When we arrived yesterday, Dr Marlin took us to the field to watch the pouring of the concrete. The real reason for the pavement was to keep us from digging later and finding the electro-magnets. Dr Marlin also introduced us to his two assistants, supposedly from India. Where do you really come from, Mustapha?”
“From Mexico City, Señor. Ali and I have had a Hindu act for some time.”
“You might have chosen better names,” said my uncle.” ‘Mustapha’ and ‘Ali’ sound more like Mohammedans than Hindus… To come to this morning. At the start of the demonstration Mustapha, Ali, and Dr Marlin were all present on the pavement. But that was the last time the three were really together until we found Ali in the water.
“Dr Marlin ‘forgot’ his ink-pad, and we three, with Ali, went to the laboratory to take the finger-prints. As soon as we had left, Mustapha produced the hollow dummy of himself from some hiding-place nearby (perhaps in the hedge) and arranged it in a sitting position on the pavement. Leaving it there, he, himself, ran up to the house.
“When we came back from the laboratory we never doubted that the dummy was Mustapha. (But remember, Jimmy, ‘Mustapha never moved’ when you gave that loud sneeze.) Dr Marlin and Ali rejoined ‘him’ on the pavement and closed all four curtains.
“Then Dr Marlin ‘discovered’ that the rope was ‘defective’ and sent ‘Mustapha’ for another one. What really happened was that the hollow dummy was placed on the cycle, and Ali crept inside it, came through the curtains and rode rapidly up to the house in the semblance of Mustapha. He had no trouble balancing on the tricycle; all he had to do was to sit still and steer. We never doubted that Ali was still behind the curtains, but, really, at that time Dr Marlin was there alone.
“When Ali reached the house, out of our sight, he emerged from the dummy, took it upstairs and hid it; while the real Mustapha walked back to the field, to give Ali more time, and ‘returned’ to us with another rope.”
“But,” I objected, “we saw Ali at the top of the rope.”
“No, Jimmy, we only thought we did. After the real Mustapha rejoined Dr Marlin behind the curtains, he started a chanting wail while Dr Marlin pressed a concealed switch – probably in one of the iron rods. This turned on the electro-magnets underneath and, as if by magic, the ‘rope’ rose in the air.
“Then either Dr Marlin or Mustapha brought from his pocket a collapsed rubber dummy which, when inflated, was an exact life-sized replica of Ali. Incidentally, that was why Ali had to shave his head. Hair would be hard to imitate, but the rubber looked just like dark skin.
“Instead of using air, Dr Marlin inflated the rubber dummy with helium. I don’t know just how; did you have a small cylinder of it under your robe, Mustapha?”
“No, Señor, the helium was under pressure in a tank beneath the concrete. One of the iron rods was really a pipe with a concealed nozzle. It took only an instant to inflate the dummy, which looked exactly like Ali. Dr Marlin paid three thousand dollars to have it made by an expert in magical supplies in Mexico City.”
“Next,” continued my uncle, “Dr Marlin placed a loin-cloth on the figure to weigh it down in position, and attached the dummy with dark threads to the bottom of the ‘rope’. Then he fired a blank cartridge, set fire to the curtains, and under cover of the dense smoke the released dummy, filled with helium and exactly weighted with a light ballast, rose to the top of the ‘rope,’ where the large knot prevented it from going higher. You must have used a very light loin-cloth, Mustapha?”
“Made of paper, Señor.”
“I see. That instant must have been the trickiest part of the whole illusion. We might notice that ‘Ali’ was rising, not climbing. But the dense smoke and the thrashing about of the ‘rope’ – caused by slight magnetic variations-entirely deceived us. Then, too, our critical faculties had just been almost paralysed by the miraculous rising of the ‘rope.’ After that we were in a state to see and believe almost anything. I don’t say we would have been fooled a second time, but Dr Marlin only had to make the demonstration once.”
“It certainly fooled me,” I said.
“No more than me, Jimmy. Next the smoke cleared, and in the air above us we saw ‘Ali’ at the top of the rope – not for long, but long enough to take photographs. Then Dr Marlin raised his pistol; but this time, instead of a blank he fired a real bullet, which pierced the dummy. The dummy instantly collapsed, and the shrunken rubber was drawn back inside the loin-cloth where we couldn’t see it as it fell to the ground. Ali had vanished before our eyes! What happened to the paper loin-cloth, Mustapha?”
“I picked it up, Señor, and by sleight-of-hand exchanged it for a real one I had under my robe. I gave the real one to Dr Marlin, who handed it to you.”
The police inspector broke in, “All this is most interesting, Señor Dobbs, but what about the murder?”
“We will come to that in a minute. The plan was that after the demonstration we should find Ali on the island-rematerialized there by magic-or rather by supra-normal powers. Apparently the only boat was still on this side, but there must have been another one hidden. Did it have a silent engine, Mustapha?”
“Yes, Señor, it was a small aluminium canoe with a battery and electric motor. Dr Marlin had it hidden, hung above the water, under the floor of the wharf. Ali was supposed to discard his loincloth, launch the canoe, cross to the island, and then sink the boat to complete the illusion.”
“Now we come to the first death,” my uncle said. “Just what happened, I don’t know. My guess would be that before the demonstration Ali demanded more money than Dr Marlin wished to pay him. Mustapha, do you know about it?”
A look of misery crossed the bearded face. “I didn’t, but I do now. The boy was too ambitious. Dr Marlin told me just before he himself died that Ali demanded half of the entire reward, instead of the ten thousand dollars apiece that we had been promised. He threatened to give the whole thing away to you if Dr Marlin didn’t agree.”
“So that was it,” my uncle said. “No doubt he promised Ali everything, and then killed him before he could try to collect. Dr Marlin must have tampered with the boat.”
“He boasted of it to me!” Mustapha cried angrily. “He opened a seam in the bottom and filled it with a plastic that would dissolve soon after Ali launched the canoe. It must have sunk about halfway across. But Ali was a better swimmer than Dr Marlin thought. He nearly managed to keep up until we came.”
“Surely you suspected something afterwards?” my uncle asked.
“I did, Señor, but I wasn’t sure. So I put the dummy of myself at the window while you two were in the dark-room, and went outside to have it out with Dr Marlin. He was ready for me though, and pulled a gun with a silencer out of his pocket. He told me how Ali had died, and then forced me to the edge of the cliff and tried to push me off-apparently a grief-stricken suicide. But he didn’t know that I had a knife in my sleeve. I threw it and it pierced his heart. Then I lost my head, tossed his gun into the water, and ran back to my room to hide the dummy in the closet. I deeply regret, Señor, that I accused you, but I didn’t think anyone would believe me.”
“Don’t worry, Mustapha,” my uncle said. “The police, no doubt, will recover Dr Marlin’s pistol and raise the canoe from the bay. That evidence will prove your story of self-defence. But it’s fortunate for me that I happened to notice the magnetized watches. I suppose that Dr Marlin never thought of them giving the show away.”